WO2022047652A1

WO2022047652A1 - End cover assembly, battery cell, battery, powered device, and liquid injection method

Info

Publication number: WO2022047652A1
Application number: PCT/CN2020/112983
Authority: WO
Inventors: 陈新祥; 郑于炼; 黄守君; 王鹏; 李伟
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2020-09-02
Filing date: 2020-09-02
Publication date: 2022-03-10
Also published as: KR20220148283A; EP3993152A1; EP3993152A4; JP2023521121A; US20220131218A1; CN114930636A

Abstract

The present application relates to an end cover assembly, a battery cell, a battery, a powered device, and a liquid injection method. The end cap assembly (10) is used in the battery cell (600), and comprises an end cover (1), seal (2) and a cover body (3). The end cover (1) is provided with a first hole (11) for injecting an electrolyte, the seal (2) is used for sealing the first hole (11), the cover body (3) is used for covering at least a portion of the seal (2), and the cover body (3) is able to rotate relative to the end cover (1) in order to implement detachable connection between the cover body (3) and the end cover (1). A second hole (21) is provided in one of either the seal (2) or the cover body (3), and a protrusion (31) is provided on the other of either the seal (2) or the cover body (3), the protrusion (31) being used for insertion into the second hole (21) and the protrusion (31) and the second hole (31) being able to rotate relative to each other, in order to implement rotatable connection between the seal (2) and the cover body (3).

Description

End cap assembly, battery cell, battery, electrical device and liquid injection method

technical field

The present application relates to the field of battery technology, and in particular, to an end cap assembly, a battery cell, a battery, an electrical device and a liquid injection method.

Background technique

Lithium-ion and other batteries have the advantages of high energy density, high power density, many cycles, and long storage time, and have been widely used in electric vehicles.

How to prolong the battery life of electric vehicles has always been a difficult problem in the industry.

SUMMARY OF THE INVENTION

An object of the present application is to provide a battery cell with improved performance.

According to a first aspect of the present application, there is provided an end cap assembly for a battery cell, comprising:

an end cap, which is provided with a first hole for injecting electrolyte;

a seal for sealing the first hole; and

a cover body for covering at least part of the sealing member, and the cover body is rotatable relative to the end cap to realize the detachable connection between the cover body and the end cap;

Wherein, one of the sealing member and the cover body is provided with a second hole, and the other of the sealing member and the cover body is provided with a boss, the boss is used to be inserted into the second hole, and the boss and the second hole can rotate relative to each other, In order to realize the rotatable connection between the seal and the cover.

By arranging the seal and the cover to be connected to each other, when the first hole is opened or closed, the seal and the cover can be disassembled or installed as a whole, which simplifies the operation steps, shortens the operation time, and improves the operation efficiency.

In some embodiments, the boss and the second hole are in an interference fit to realize the connection between the two.

Interference fit is adopted between the boss and the second hole, which can not only realize the connection between the sealing element and the cover body, but also enable relative rotation between the sealing element and the cover body. The rotatable connection between the sealing element and the cover body is realized by means of interference fit, no new components and new structures are required, and the manufacturing cost is low.

In some embodiments, the boss includes a first insertion portion, a hole wall of the second hole is provided with a first accommodating portion, and the first insertion portion is accommodated in the first accommodating portion to limit the separation of the seal and the cover.

By arranging the first insertion portion and the first accommodating portion, the first insertion portion is inserted into the first accommodating portion, and through the cooperation of the first inserting portion and the first accommodating portion, the sealing member and the cover body can be restricted from being separated from each other, so as to ensure that the sealing member and the cover are not separated from each other. Solid connection of the cover.

In some embodiments, in a direction perpendicular to the axis of the second hole, the cross-sectional area of the first receiving portion gradually increases in a direction away from the inserted end of the second hole, and the first inserting portion cooperates with the first receiving portion , to limit the separation of the seal and the cover.

The cross-sectional area of the first accommodating part gradually increases in the direction away from the inserted end of the second hole, which can increase the difficulty of the first inserting part detaching from the first accommodating part, thereby limiting the detachment of the limiting seal and the cover.

In some embodiments, the second hole is a blind hole.

This structure can effectively prevent impurities from entering the interior of the battery cell through the second hole, and can also effectively prevent the electrolyte in the battery cell from leaking through the second hole.

In some embodiments, the seal and the end cap are relatively fixed in the circumferential direction of the first hole.

The seal and the end cover are kept relatively fixed in the circumferential direction, which can prevent the seal from rotating with the cover relative to the end cover when the cover rotates relative to the end cover, reducing the wear between the seal and the end cover. Reduce the impact on the sealing effect.

In some embodiments, the axis of rotation of the cover relative to the seal is collinear with the axis of the first bore.

If the axis of rotation of the cover relative to the seal is not collinear with the axis of the first hole, when the cover rotates relative to the seal, the seal will be driven to rotate due to eccentricity, causing friction between the seal and the end cap. Therefore, the axis of rotation of the cover body relative to the sealing member and the axis of the first hole are set to be collinear, which can effectively ensure that the sealing member does not rotate with the cover body when the cover body rotates relative to the end cover, and reduces the gap between the sealing member and the end cover. friction.

In some embodiments, the seal includes a seal post inserted into the first hole. The sealing element effectively seals the first hole through the sealing column to prevent leakage of electrolyte and entry of impurities.

In some embodiments, the seal post is a non-rotational body, and the shape of the first hole cooperates with the seal.

Setting the sealing column as a non-rotating body can effectively ensure the relative fixation between the sealing element and the end cover, and prevent the relative rotation between the sealing element and the end cover from causing wear.

In some embodiments, the sealing post is an interference fit with the first hole.

By setting the fit between the sealing column and the first hole as an interference fit, the difficulty of rotating the sealing column in the first hole can also be increased, and the relative fixing of the sealing member and the end cover can be realized.

In some embodiments, the boss is in an interference fit with the second hole, and the friction coefficient of the contact surface of the sealing post and the first hole is greater than the friction coefficient of the contact surface of the boss and the second hole.

In some embodiments, the sealing member further comprises a thrust table connected with the sealing column, the thrust table is located between the cover body and the end cap, and the thrust table is matched with the end face of the first hole.

When an interference fit is adopted between the sealing column and the first hole and between the boss and the second hole, the friction coefficient of the contact surface between the sealing column and the first hole is set to be greater than the friction coefficient of the contact surface between the boss and the second hole , when the external force applied to the cover can make the cover rotate relative to the seal, the external force is not enough to make the seal rotate relative to the end cover, so the relative fixation of the seal and the end cover can be ensured, reducing the number of seals and the end cover. wear between.

In some embodiments, the boss is a body of revolution. This structure is beneficial to realize the rotation of the boss in the second hole.

In some embodiments, the end cap is provided with a second accommodating portion arranged along the circumference of the first hole, the second accommodating portion is used for accommodating at least a part of the cover body to realize the limitation of the cover body, and the second accommodating portion is located at the end The side of the cover away from the interior of the battery cell.

The second accommodating portion can accommodate a part of the cover body to limit the cover body, limit the freedom degree of the cover body in its height direction, prevent the cover body from separating from the end cap, and realize the relative fixation between the cover body and the end cap. At the same time, the cover body can at least partially cover the sealing element, so after the cover body is restricted by the end cap in terms of freedom in the height direction, the sealing element is also pressed under the cover body, which also realizes the fixing of the sealing element. .

In some embodiments, the cover body is rotatable relative to the end cover and includes a limiting portion. When the cover body rotates to the first position, the limiting portion is located in the second accommodating portion to limit the separation of the cover body and the end cover; when the cover body rotates When reaching the second position, the limiting portion and the second accommodating portion are displaced along the circumferential direction of the first hole, so as to realize the separation of the cover body and the end cover. The detachable connection between the end cap and the cover body can be achieved by providing the limiting portion to cooperate with the second accommodating portion.

In some embodiments, the boss and the second hole are configured to be relatively rotatable at least during rotation of the cover from the first position to the second position.

In some embodiments, the end cap further includes a guide portion that communicates with the second accommodating portion, and the limiting portion is used to enter the second accommodating portion through the guide portion, or to be separated from the end cap through the guide portion.

By providing the guide portion, the limiting portion can be more smoothly entered into or separated from the second accommodating portion, thereby improving the convenience of operation and further improving the operation efficiency.

In some embodiments, the end cap includes an end cap body and an installation part, the installation part is arranged on the surface of the end cap body and is arranged around the first hole, the second accommodating part is arranged in the installation part or the second accommodating part is connected by the installation part and the installation part. The end cap body is enclosed and formed.

In some embodiments, the sealing member includes a sealing column inserted into the first hole, an end of the sealing column close to the interior of the battery cell is provided with a guiding slope, and the length of the guiding slope along the axis direction of the first hole is greater than that of the mounting member along the first hole. The length of the hole in the axial direction.

Since the thin plate-like structure of the end cap is not easy to process complicated structures, the second accommodating portion can be easily formed by arranging the mounting parts, which can reduce the processing difficulty of the end cap.

According to a second aspect of the present application, there is provided a case assembly for a battery cell, comprising:

a casing, which is used for connecting with the end cap to form an outer casing of the battery cell, and the casing is provided with a first hole for injecting electrolyte;

a seal for sealing the first hole; and

According to a third aspect of the present application, a battery cell is provided, comprising:

An electrode assembly and a casing for accommodating the electrode assembly, the casing comprising a casing and an end cap assembly as claimed in any one of claims 1 to 19, the end of the casing having an opening, and the end cap assembly covering the opening of the end of the casing; or ,

An electrode assembly and a housing for accommodating the electrode assembly, the housing comprising an end cap and the casing assembly of claim 20, the end of the casing having an opening, the end cap covering the opening of the end of the casing.

According to a fourth aspect of the present application, there is provided a battery including a plurality of the above-mentioned battery cells.

According to a fifth aspect of the present application, an electrical device is provided, comprising the above-mentioned battery cells, wherein the battery cells are used to provide electrical energy.

According to a sixth aspect of the present application, there is provided a liquid injection method for a battery cell, comprising:

inject the electrolyte through the first hole on the outer shell of the battery cell;

taking the seal and the cover in the connected state to the first hole, and sealing the first hole with the seal while the seal and the cover are connected, and covering at least part of the seal with the cover; and

The cover body is rotated relative to the seal to achieve relative fixation of the cover body and the housing.

In some embodiments, the liquid injection method of the battery cell further includes:

Remove the cover and seal from the housing while remaining connected.

In some embodiments, the sealing member is provided with a second hole, the cover body is provided with a boss, the boss is inserted into the second hole, the second hole is a blind hole, and the electrolyte is injected through the first hole on the outer shell of the battery cell. Before the injection, the injection method also includes:

piercing the bottom wall of the second hole so that the second hole communicates the interior of the battery cell with the external environment to relieve pressure inside the battery cell; and

Remove the cover and seal from the housing.

Rotating the cover body from the first position to the second position, so that the limiting part of the cover body and the second accommodating part of the side of the casing away from the interior of the battery cell are displaced along the circumferential direction of the first hole; and

The cover body is rotated from the second position to the first position, so that the limiting portion enters the second accommodating portion, so as to limit the separation of the cover body and the sealing member from the housing.

rotating the cover body from the first position to the second position, so that the limiting portion and the second accommodating portion are displaced along the circumferential direction of the first hole; and

Remove the cover and seal from the housing while remaining connected.

According to a seventh aspect of the present application, there is provided a liquid injection device for a battery cell, comprising:

A liquid injection mechanism for injecting the electrolyte into the casing through the first hole provided on the casing; and

The disassembly and assembly mechanism is used to take the seal and the cover body in the connected state to the first hole before the first hole is sealed by the seal, and seal the first hole through the seal while the seal and the cover are kept connected. At least part of the sealing member is covered by the cover body, and after the sealing member is matched with the first hole, the cover body is driven to rotate relative to the sealing member, so as to realize the relative fixing of the cover body and the casing.

The end cap assembly of the embodiment of the present application is rotatably connected to the cover body through a sealing member. During the secondary injection, the sealing member and the cover body can be sealed together in the first hole or separated from the first hole as a whole to close the Or open the first hole to realize the secondary injection, while simplifying the operation steps of the secondary injection, effectively shortening the operation time and improving the operation efficiency.

Description of drawings

The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation of the present application. In the attached image:

1-A is a schematic diagram of the appearance of some embodiments of vehicles using the battery cells of the present application;

1-B is a schematic structural diagram of some embodiments of the battery of the present application;

1-C is a schematic structural diagram of some embodiments of the battery module of the present application;

1-D are exploded views of some embodiments of the battery cells of the present application;

2 is an exploded view of some embodiments of the end cap assembly of the present application;

3 is a schematic assembly diagram of some embodiments of the sealing member and the cover body in the end cap assembly of the present application;

4 is a cross-sectional view of some embodiments of the end cap assembly of the present application;

5 is a schematic structural diagram of some embodiments of the sealing member in the first embodiment;

6 is a cross-sectional view of some embodiments of the seal in the first embodiment;

FIG. 7 is a schematic structural diagram of some embodiments of the cover body in the first embodiment;

8 is a schematic structural diagram of some embodiments of the cover body in the first embodiment from another angle;

9 is a cross-sectional view of some embodiments of the cover body in the first embodiment;

10 is a cross-sectional view of the matching structure of the cover body and the sealing member in the second embodiment;

Figure 11 is a cross-sectional view of some embodiments of the seal in the second embodiment;

FIG. 12 is a cross-sectional view of the matching structure of the cover body and the sealing member in the third embodiment;

13 is a cross-sectional view of some embodiments of the cover body in the third embodiment;

14 is a cross-sectional view of some embodiments of the seal in the third embodiment;

15 is a cross-sectional view of the matching structure of the cover body and the sealing member in the fourth embodiment;

16 is a cross-sectional view of some embodiments of the seal in the fourth embodiment;

17 is a schematic structural diagram of some embodiments of the cover body in the fourth embodiment;

18 is a cross-sectional view of some embodiments of the cover body in the fourth embodiment;

19A and 19B are a schematic structural diagram and a bottom view of the sealing member in the fifth embodiment, respectively;

20A and 20B are schematic views of the front and rear structures of some embodiments of the mounting components in the present application, respectively;

21A and 21B are a top view and an A-A cross-sectional view of some embodiments of the mounting components in the present application, respectively;

FIG. 22 is a partial structural schematic diagram of the end cap 1 in the application;

FIG. 23 is a schematic diagram of the matching structure of the end cap, the sealing member and the cover body in some embodiments of the present application;

FIG. 24 is a schematic structural diagram of some embodiments of housing assemblies for battery cells of the present application;

FIG. 25 is a schematic flowchart of some embodiments of the battery cell liquid injection method of the present application;

FIG. 26 is a schematic diagram of the composition of some embodiments of the liquid injection device of the present application.

detailed description

The present application is described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Aspects so defined may be combined with any other aspect or aspects, unless explicitly stated otherwise. In particular, any feature considered preferred or advantageous may be combined with one or more other features considered preferred or advantageous.

Terms such as "first" and "second" appearing in this application are only for the convenience of description, to distinguish different components with the same name, and do not indicate a sequence or a primary-secondary relationship.

Also, when an element is referred to as being "on" another element, it can be directly on the another element, or it can be indirectly on the another element with one or more intervening intervening elements therebetween element. Also, when an element is referred to as being "connected to" another element, it can be directly connected to the another element or be indirectly connected to the another element with one or more intervening elements interposed therebetween. In the following, the same reference numerals refer to the same elements.

The "plurality" in this application refers to two or more, and similarly, "multiple groups" refers to two or more groups.

In order to clearly describe the various orientations in the following embodiments, for example, the coordinate system in FIG. 1-D defines various directions of the battery, the x-direction represents the length direction of the battery cell 600; the y-direction is perpendicular to the x-direction in the horizontal plane , represents the width direction of the battery cell 600 ; the z direction is perpendicular to the plane formed by the x and y directions, and represents the height direction of the battery cell 600 . Based on this orientation definition, descriptions of orientations or positional relationships indicated by "upper", "lower", "top", "bottom", "front", "rear", "inner" and "outer" are adopted. It is only for the convenience of describing the present application, rather than indicating or implying that the referred device must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the protection scope of the present application.

There are many problems that cause the service life of lithium-ion batteries. Over the years, those skilled in the art have tried to solve the problems from many different angles, but the expected results have not been achieved.

As part of the invention and creation process of the present application, the inventor found through analysis and research that one of the reasons for the problem of battery service life is that the battery undergoes multiple charge and discharge cycles during use, and the electrolyte inside the battery will inevitably undergo irreversible reactions. consumption, the battery capacity will decrease accordingly. Therefore, the inventors found that if the electrolyte inside the battery can be supplemented during the use of the battery, the reduction of the battery capacity can be effectively slowed down and the service life of the battery can be improved.

Lithium-ion batteries are mainly composed of four parts: positive electrode material, negative electrode material, electrolyte, and diaphragm. The electrolyte is an ionic conductor that conducts between the positive and negative electrodes of the battery, and is generally composed of electrolyte lithium salt and organic solvent. In order to prevent the electrolyte from leaking out and polluting the surrounding air and environment during use, or water vapor or metal particles entering the battery, causing short circuit of the positive and negative electrodes, the battery has high requirements on the sealing of the structure. In the related art known to the inventor, the electrolyte perfusion of the battery is usually carried out in the production stage. After the electrolyte perfusion is completed, in order to ensure the sealing of the battery, the injection hole is usually closed by laser welding.

This kind of battery is difficult to refill during use. If you want to refill, you need to destroy the structure of the laser welding seam, which is difficult to re-seal, and will cause irreversible damage to the structure of the battery, affecting the performance of the battery.

In view of this, the present application provides a battery cell with a detachable liquid injection member, which can conveniently realize the secondary liquid injection of the battery. The process of injecting the electrolyte into the battery according to the required amount by reserving the injection hole is divided into primary injection and secondary injection. Secondary injections may also be referred to as supplementary injections, further injections, etc. The meaning of secondary injection is the process of replenishing or replacing the electrolyte in the battery, or adding or replenishing any solid, liquid or gas to the battery. By realizing convenient secondary liquid injection, the present application can effectively slow down the reduction of the capacity of the battery cell and improve the service life of the battery.

During the use of the battery, the electrolyte undergoes an electrochemical reaction inside the battery, so it is necessary to ensure the sealing of the battery to prevent the leakage of the electrolyte. To this end, in the embodiment of the end cap assembly provided in the present application, the end cap assembly includes a sealing member for sealing the liquid injection hole and a cover body for fixing the sealing member. By arranging the sealing member, the liquid injection hole can be effectively sealed, and by arranging the cover, the stability of the sealing member can be ensured, and the sealing member can be prevented from being separated from the liquid injection hole.

As part of the invention and creation process of the present application, the inventor also found that during the secondary injection, the injection hole is generally opened first, and then the electrolyte is injected into the interior of the battery through the injection hole, and finally the injection hole is sealed. Specifically, when opening the liquid injection hole, the cover body needs to be removed first, and then the sealing member is removed; and when the liquid injection hole is sealed, the sealing member needs to be installed first, and then the cover body needs to be installed. It can be seen that when opening and sealing the liquid injection hole, the operation steps are more complicated.

After discovering the problem that the operation steps are relatively complicated when opening and sealing the injection hole, the inventor conducted careful analysis and research, and found that an important reason for the complicated operation steps is that the seal and the cover are separate structures. When disassembling the seal and the cover, it needs to be installed or disassembled one by one. For battery cell products, it has extremely high requirements on sealing, so the positioning accuracy of the seal and cover during assembly is also very high. It is required to install or disassemble the seal and the cover one by one, which will inevitably increase the difficulty of disassembly and assembly, and the steps will be more complicated.

Based on the above findings, the present application proposes an end cap assembly, a battery cell, a battery and an electrical device, which can rotatably connect the sealing member and the lid body. During the secondary liquid injection, the sealing member and the lid body can be used as The whole is sealed in the first hole or separated from the first hole, so as to close or open the first hole, and realize the secondary injection; at the same time, the operation steps of the secondary injection are simplified, the operation time of the secondary injection is shortened, and the In addition, it can effectively ensure the sealing effect, prevent the leakage of the electrolyte of the battery cell, and improve the performance and service life of the battery cell.

Based on the above ideas, the present application provides an end cap assembly, a housing assembly, a battery cell, a battery, an electrical device, a liquid injection method, and a liquid injection device.

The electrical device includes a battery unit 600 for providing electrical energy to the device. As shown in FIG. 1-A, the electrical device may be a vehicle 100, such as a new energy vehicle, which may be a pure electric vehicle, a hybrid vehicle or a Extended-range vehicles, etc.; or electrical devices can also be drones or ships. The vehicle 100 includes a motor 200, a controller 300 and a battery 400, wherein the motor 200 is used to drive the movement of the vehicle, and the controller 300 can control the forward and reverse of the vehicle and the speed of the vehicle, etc. The battery 400 provides electric power for the vehicle and can be used for The driving motor 200 rotates, and the motor 200 drives the wheels to rotate, so as to realize the driving effect on the vehicle 100 .

The battery cell 600 capable of secondary liquid injection can reduce the replacement frequency of the battery cell of the electrical device, save costs, and improve the reliability and power performance of the device. By using the device of the battery cell 600 provided by the present application, the operation steps of the secondary liquid injection can also be simplified, the operation time can be shortened, and the efficiency of the secondary liquid injection can be improved.

In order to make the battery achieve higher power to meet the usage requirements, as shown in FIG. 1-B , a battery 400 may be provided in the electrical device. In some embodiments, the battery 400 may include a plurality of battery cells 600 . A plurality of battery cells 600 may directly form a battery, or a battery module 500 may be formed first, and then the battery module 500 may be formed into a battery. The battery 400 may include a first case 401 and a second case 402 , wherein the first case 401 and the second case 402 are fastened to each other, and a plurality of battery cells 600 are arranged in the first case 401 and the second case 402 The housing 402 encloses the formed space.

As shown in FIG. 1-C , the battery module 500 includes a plurality of battery cells 600 , and the plurality of battery cells 600 can be connected in series, in parallel or in a mixed connection to achieve larger capacity or power. For example, as shown in FIG. 1-C, the battery cells 600 can be placed vertically, the height direction of the battery cells 600 is consistent with the vertical direction, and a plurality of battery cells 600 are arranged side by side along the width direction; or the battery cells 600 can be flat The width direction of the battery cells 600 is consistent with the vertical direction, and a plurality of battery cells 600 can be stacked in at least one layer along the width direction, and each layer includes a plurality of battery cells 600 spaced along the length direction.

In order for those skilled in the art to clearly understand the improvements of the present application, the overall structure of the battery cell 600 is first described.

As shown in FIGS. 1-D , the battery cell 600 includes an end cap assembly 10 , an adapter 20 , an electrode assembly 30 and a housing 40 , wherein the electrode assembly 30 includes a tab 301 , and the adapter 20 is connected to the electrode assembly 30 . , the electrode assembly 30 is arranged in the casing 40, and the casing 40 is filled with electrolyte. The top of the casing 40 is provided with an opening 41 , and the end cap assembly 10 is used to close the opening 41 and seal the adapter 20 and the electrode assembly 30 inside the casing 40 . The housing 40 may be square, cylindrical or other shapes.

According to actual use requirements, the electrode assembly 30 can be provided in a single or multiple. As shown in Figures 1-D, at least two independently wound electrode assemblies 30 may also be provided in the battery. The electrode assembly 30 can be formed by winding or stacking the first pole piece, the second pole piece and the separator between the first pole piece and the second pole piece, wherein the separator is interposed between the first pole piece and the insulator between the second pole piece. The main body portion has two opposite end surfaces. In this embodiment, the first pole piece is exemplified as a positive electrode piece, and the second pole piece is a negative electrode piece for description. The positive active material is coated on the coated area of the positive electrode sheet, and the negative active material is coated on the coated area of the negative electrode sheet. A plurality of uncoated regions extending from the coated regions of the body portion are stacked as tabs. The electrode assembly 30 includes two tabs 301 , a positive tab and a negative tab. The positive tabs extend from the coated areas of the positive tabs, and the negative tabs extend from the coated areas of the negative tabs.

The end cap assembly 10 is arranged on the top of the electrode assembly 30. As shown in Figures 1-D and 2, the end cap assembly 10 includes an end cap 1 and two electrode terminals 5, which are respectively a positive terminal and a negative terminal, Each electrode terminal 5 is provided with an adapter 20 correspondingly, and the adapter 20 is located between the end cap assembly 10 and the electrode assembly 30 . The end cover 1 is provided with a mounting hole corresponding to the electrode terminal 5, the electrode terminal 5 is fixed in the corresponding mounting hole, and a sealing ring may be provided between the electrode terminal 5 and the mounting hole. For example, the tab 301 of the electrode assembly 30 in FIG. 1-D is located at the top, the positive tab is connected to the positive terminal through one adapter 20 , and the negative tab is connected to the negative terminal through another adapter 20 .

Optionally, in some other embodiments, the battery cell 600 may include two end cap assemblies 10 , which are respectively disposed on both ends of the housing 40 , and an electrode terminal 5 is disposed on each end cap assembly 10 .

An explosion-proof member 6 may also be provided on the end cover 1 to release the gas in the battery cell 600 in time when there is too much gas in the battery cell 600 to avoid explosion. The end cover 1 is provided with an exhaust hole, the exhaust hole can be located in the middle position of the end cover 1 along the length direction, and the exhaust hole can be located between two installation holes for installing the electrode terminal 5 . Under normal conditions, the explosion-proof member 6 is sealed and installed in the exhaust hole, and gas is generated when the battery cells 600 are charged and discharged. When the air pressure in the outer casing rises above the preset value, the explosion-proof member 6 is opened, and the gas passes through the explosion-proof member 6 release outwards. The explosion-proof member 6 can also be used for blasting when the temperature in the battery cell 600 is too high, so as to achieve a cooling and explosion-proof effect by releasing the gas in the battery cell.

In some embodiments, as shown in FIG. 2 , the battery cell 600 is provided with a first hole 11 for injecting electrolyte into the interior of the battery cell 600 , and the battery cell 600 further includes a first hole 11 for closing the first hole 11 . injection components.

After describing the overall structure and application of the battery cell 600 , the liquid injection member of the present application will be described in detail below. A plurality of embodiments are presented, and the common points of the embodiments are first given below.

As shown in FIGS. 1-D to 25 , the present application provides an end cap assembly 10 for a battery cell 600 . In some embodiments, the end cap assembly 10 includes an end cap 1 , a seal 2 and a cap body 3 .

As shown in FIG. 2 , the end cap 1 is provided with a first hole 11 for injecting electrolyte, and the first hole 11 can be a circular hole, an oval hole, a polygonal hole or a hole of other shapes. The first holes 11 may be disposed along the height direction of the battery cells 600 , that is, disposed along the height direction of the end cap 1 , or may be disposed obliquely with respect to the height direction of the end cap 1 . The first hole 11 may be provided between the mounting hole for mounting the electrode terminal 5 and the exhaust hole for mounting the explosion-proof member 6 .

The seal 2 is used to seal the first hole 11 . The sealing member 2 can be sealed around the first hole 11 or inserted into the first hole 11 to effectively seal the first hole 11 and prevent the electrolyte in the battery cell 600 from leaking through the first hole 11 .

The cover body 3 is used to cover at least part of the sealing member 2 to prevent the sealing member 2 from being separated from the end cap 1 . The cover body 3 can press the sealing member 2 to deform the sealing member 2 to improve the sealing effect, or only contact the sealing member 2 to limit its degree of freedom in the height direction; In the case of independently closing the first hole 11 , the lid body 3 may be spaced apart from the sealing member 2 in the height direction. The cover body 3 can completely cover the sealing member 2, so as to apply pressure to the sealing member 2, limit the position or prevent external impurities from entering the interior of the battery cell 600; the sealing member 2 is tightly fitted with the first hole 11 and can independently close the first hole In the case of 11, the cover body 3 may partially cover the sealing member 2.

The cover body 3 is rotatable relative to the end cover 1 , and the cover body 3 is detachably connected to the end cover 1 by means of rotation. For example, the cover body 3 is rotatable in a plane perpendicular to the height direction, and the rotation axis may be the axis of the first hole 11 .

In the present application, the cover body 3 can be separated from the end cap 1 by rotating the cover body 3, and the secondary liquid injection can be realized. Through convenient secondary injection, the present application can effectively slow down the capacity reduction of the battery cells 600 and improve the service life of the battery.

Further, the liquid injection member is detachable. After the liquid injection member is disassembled, the first hole 11 communicates the inside of the casing 40 with the outside atmosphere, and can discharge the gas in the casing 40 or the air bubbles between the pole pieces. By discharging air bubbles between the pole pieces and shortening the gap between the pole pieces, the cycle performance of the battery cell 600 can be improved, and the service life of the battery cell 600 can be further improved. By discharging the gas in the casing of the battery cell 600 , the present application can also release the pressure in the casing 40 , thereby reducing the continuous force of the gas in the casing 40 on the explosion-proof member 6 , and reducing the creep rupture of the explosion-proof member 6 resulting in the battery cell. The risk of liquid leakage or water vapor entering the 600 will shorten the service life, thereby further improving the service life of the battery cell, and at the same time, it can reduce the force exerted by the expansion of the battery cell 600 on other structures due to the large gas inside the battery cell 600, so as to avoid other structures due to Excessive expansion force of the battery cells 600 may cause structural damage, thereby increasing the service life of the battery.

In the present application, the cover body 3 and the end cover 1 can be combined or separated by the rotation of the cover body 3, thereby realizing the closing and opening of the first hole 11, so that a detachable structure is formed between the cover body 3 and the end cover 1. Opening the cover body 3 will not destroy the liquid injection structure, and after the secondary liquid injection is completed, the first hole 11 can be reliably closed, which can ensure the reliability of the battery cell after the secondary liquid injection. Therefore, the appearance of the battery cell 600 remains the same as before the liquid injection, and does not affect the use after the secondary liquid injection. Further, because the first hole 11 is directly sealed by rotating the cover 3, it is not necessary to seal the first hole 11 by laser welding, which reduces the cleaning steps of the first hole 11 before laser welding and improves the battery production efficiency. .

As shown in FIG. 3 , one of the sealing member 2 and the cover body 3 is provided with a second hole 21 , and the other of the sealing member 2 and the cover body 3 is provided with a boss 31 , and the boss 31 is used to insert the second hole 21 The middle and convex boss 31 and the second hole 21 can rotate relative to each other, so as to realize the rotatable connection between the sealing member 2 and the cover body 3 .

Specifically, in some embodiments, the sealing member 2 is provided with a second hole 21 , the cover body 3 is provided with a boss 31 , and the boss 31 is inserted into the second hole 21 to realize the sealing member 2 and the cover body 3 . rotatably connected. In other embodiments, the sealing member 2 is provided with a boss 31, the cover body 3 is provided with a second hole 21, and the boss 31 is inserted into the second hole 21, so that the sealing member 2 and the cover body 3 can be rotatably arranged. connect.

By arranging the sealing member 2 and the cover body 3 to be connected to each other, when the first hole 11 is opened or closed, the sealing member 2 and the cover body 3 can be installed or removed as a whole, which simplifies the operation steps, shortens the operation time, and improves the operation. effectiveness. After the sealing member 2 and the cover body 3 are installed, impurities can be prevented from entering the interior of the battery cell 600 through the first hole 11 .

Further, the cover body 3 is rotatable relative to the end cover 1. By setting the sealing member 2 and the cover body 3 to be rotatably connected, when the cover body 3 is rotated, it can be prevented that the cover body 3 drives the sealing member 2 to have a linkage. It is beneficial to maintain the relative fixation of the sealing member 2 and the end cover 1, and prevent the sealing member 2 and the end cover 1 from being relatively rotated to cause wear and tear, thereby reducing the sealing effect.

The matching structure of the sealing member 2 and the cover body 3 in the present application will be described in detail below with reference to FIGS. 4 to 19B .

As shown in FIG. 4 to FIG. 11 , in some embodiments, the boss 31 and the second hole 21 are in an interference fit to realize the connection between the two.

The interference fit between the boss 31 and the second hole 21 can not only realize the connection between the sealing element 2 and the cover body 3 , but also enable relative rotation between the sealing element 2 and the cover body 3 . The rotatable connection between the sealing member 2 and the cover body 3 is realized by means of interference fit, without adding new components and structures, and the manufacturing cost is low.

The boss 31 and the second hole 21 are in an interference fit, that is, the boss 31 and the second hole 21 are tightly fitted, the dimensions of the boss 31 and the second hole 21 have an interference amount, and the tolerance of the second hole 21 The band is below the tolerance band of the boss 31 .

In some embodiments, the boss 31 is a body of revolution. The boss 31 is rotatable relative to the seal 2 in the second hole 21 . By setting the boss 31 as a rotating body, the rotatable connection between the sealing member 2 and the cover body 3 can be realized. The shape of the second hole 21 matches the shape of the boss 31 .

The boss 31 is a revolving body, and specifically can be a cylinder, a sphere, or a part of a sphere, or the like.

The shape of the boss 31 and the shape of the second hole 21 are matched with each other to achieve interference fit. For example, as shown in FIGS. 4 to 11 , the shape of the boss 31 is a cylinder, and the shape of the second hole 21 is a cylindrical shape that fits with the boss 31 . Alternatively, as shown in FIGS. 12 to 14 , the shape of the boss 31 is a truncated truncated cone, and the shape of the second hole 21 is a truncated truncated shape that fits with the boss 31 . Alternatively, as shown in FIGS. 15 to 18 , the shape of the boss 31 is a stepped cylinder, and the shape of the second hole 21 is a stepped circular shape matched with the boss 31 . Various embodiments of the boss 31 and the second hole 21 will be described in detail below.

As shown in FIGS. 12 to 18 , in some embodiments, the boss 31 includes a first insertion portion 311 , a hole wall of the second hole 21 is provided with a first accommodating portion 212 , and the first insertion portion 311 is accommodated in the first accommodating portion 311 . part 212 to limit the separation of the seal 2 and the cover 3 .

By arranging the first insertion portion 311 and the first accommodating portion 212, the first insertion portion 311 is inserted into the first accommodating portion 212, and through the cooperation of the first insertion portion 311 and the first accommodating portion 212, the sealing member 2 and the cover can be restricted 3 are disengaged from each other to ensure a firm connection between the seal 2 and the cover 3 .

The boss 31 may only include the first insertion portion 311 , or may include other parts besides the first insertion portion 311 . The second hole 21 may only include the first accommodating portion 212 , or may include other parts besides the first accommodating portion 212 .

The shapes of the first insertion portion 311 and the first receiving portion 212 are matched, and the two cooperate with each other to limit the separation of the sealing member 2 and the cover body 3 . Since the battery cell 600 may vibrate during use, maintaining the connection stability of the sealing member 2 and the cover body 3 is beneficial to enable the battery cell 600 to resist the loosening problem caused by vibration and improve the service life of the battery cell 600 .

As shown in FIGS. 12 to 14 , in some embodiments, in the direction perpendicular to the axis of the second hole 21 , the cross-sectional area of the first receiving portion 212 gradually increases along the direction away from the inserted end of the second hole 21 . , the first inserting portion 311 cooperates with the first accommodating portion 212 to limit the separation of the sealing member 2 and the cover body 3 .

The cross-sectional area of the first accommodating portion 212 gradually increases in the direction away from the inserted end of the second hole 21 , which can increase the difficulty of the first insertion portion 311 to escape from the first accommodating portion 212 , thereby restricting the sealing member 2 and the cover body. 3 disengage. In a direction parallel to the axis of the second hole 21 , the cross section of the first accommodating portion 212 has a trapezoidal shape.

As shown in FIGS. 15 to 18 , the boss 31 includes a first insertion portion 311 and a second insertion portion 312 , and the first insertion portion 311 and the second insertion portion 312 are both cylindrical in shape. The second hole 21 includes a third extending portion 216 and a first receiving portion 212 , the third extending portion 216 is matched with the second inserting portion 312 , and the first receiving portion 212 is matched with the first inserting portion 311 . The diameter of the first insertion part 311 is larger than the diameter of the second insertion part 312 , and the diameter of the first receiving part 212 is larger than that of the third extension part 216 , so the cooperation of the first insertion part 311 and the first receiving part 212 can limit the sealing element 2 is separated from the cover body 3.

As shown in FIGS. 4 to 18 , in some embodiments, the second hole 21 is a blind hole, that is, the end of the second hole 21 away from the cover 3 is closed. This structure can effectively prevent impurities from passing through the second hole 21 . Entering the inside of the battery cell 600 can also effectively prevent the electrolyte in the battery cell 600 from leaking through the second hole 21 .

In some embodiments, the sealing member 2 and the end cap 1 are relatively fixed in the circumferential direction of the first hole 11 .

The sealing member 2 and the end cover 1 are kept relatively fixed in the circumferential direction, which can prevent the sealing member 2 from rotating with the cover body 3 relative to the end cover 1 when the cover body 3 rotates relative to the end cover 1, reducing the number of sealing members 2 The wear between the end cap 1 and the end cap 1 reduces the influence on the sealing effect.

In the battery cell 600 provided in the present application, the sealing member 2 is sealed in the first hole 11 and pressed against the lower side of the end cover 1 . In actual use, when the rotating cover body 3 rotates relative to the end cover 1 If the cover body 3 covers most of the sealing member 2 or completely covers the sealing member 2 , it may not be possible to visually see whether the sealing member 2 under the cover body 3 is rotated relative to the end cap 1 . In order to solve this problem, marks can be made on the outer surface of the sealing member 2 and the hole wall of the first hole 11 respectively. Then, after the cover body 3 is rotated, the cover body 3 is opened again, and it can be determined whether the relative position of the sealing member 2 and the first hole 11 has changed by checking the position of the mark. Marking can take the form of scribing, labeling, and the like.

In some embodiments, the axis of rotation of the cover body 3 relative to the seal 2 is collinear with the axis of the first hole 11 .

If the axis of rotation of the cover body 3 relative to the sealing member 2 is not collinear with the axis of the first hole 11, when the cover body 3 rotates relative to the sealing member 2, the sealing member 2 will be driven to rotate due to eccentricity, causing the sealing member 2 and the sealing member 2 to rotate. Because of the friction between the end caps 1, the axis of rotation of the cover body 3 relative to the seal 2 and the axis of the first hole 11 are set to be collinear, which can effectively ensure the seal 2 when the cover body 3 rotates relative to the end cap 1. It does not rotate with the cover body 3 to reduce the friction between the seal 2 and the end cover 1 .

In some embodiments, the seal 2 includes a seal post 22 inserted into the first hole 11 . The sealing member 2 effectively seals the first hole 11 through the sealing column 22 to prevent leakage of electrolyte and entry of impurities.

The sealing column 22 is inserted into the inside of the first hole 11 , which can achieve a better sealing effect on the first hole 11 .

In some embodiments, the sealing column 22 is a non-rotating body, and the shape of the first hole 11 is matched with the sealing member 2 .

Setting the sealing column 22 as a non-rotating body can effectively ensure the relative fixation between the sealing member 2 and the end cover 1, and prevent the relative rotation between the sealing member 2 and the end cover 1 from causing wear. The shape of the first hole 11 is matched with the sealing member 2 , which is beneficial to realize the sealing of the first hole 11 .

As shown in FIGS. 19A and 19B , the cross-sectional shape of the sealing post 22 is oval, and the shape of the first hole 11 is set to fit with the sealing member 2 . After the sealing post 22 is matched with the first hole 11 , the Rotation occurs in the middle, and the relative fixation of the sealing member 2 and the end cover 1 is realized.

In addition to the oval shape, in some other embodiments, the cross-sectional shape of the sealing post 22 may also be a polygonal or irregular shape.

In some embodiments, the sealing post 22 is an interference fit with the first hole 11 . The sealing post 22 has an interference fit with the first hole 11 , that is, the sealing post 22 and the first hole 11 are tightly fitted, and there is an interference between the dimensions of the sealing post 22 and the first hole 11 . The band is below the tolerance band of the seal post 22 .

By setting the fit between the sealing post 22 and the first hole 11 as an interference fit, the difficulty of rotating the sealing post 22 in the first hole 11 can also be increased, and the relative fixation of the sealing member 2 and the end cover 1 can be achieved.

In some embodiments, the sealing post 22 is in interference fit with the first hole 11 , the boss 31 is in interference fit with the second hole 21 , and the frictional force between the sealing post 22 and the first hole 11 is greater than that between the boss 31 and the first hole 11 . The friction force between the two holes 21 . After this arrangement, when the external force applied to the cover body 3 can make the cover body 3 rotate relative to the sealing member 2, the external force is not enough to overcome the friction force between the sealing member 2 and the end cover 1 and cause the sealing member 2 and the end cover to rotate. 1 is relatively rotated, so the relative fixation of the seal 2 and the end cover 1 can be ensured, and the wear between the seal 2 and the end cover 1 can be reduced.

In some embodiments, the sealing post 22 is in interference fit with the first hole 11 , the boss 31 is in interference fit with the second hole 21 , and the friction coefficient of the contact surface between the sealing post 22 and the first hole 11 is greater than that between the boss 31 and the first hole 11 . The friction coefficient of the contact surfaces of the two holes 21 .

When an interference fit is adopted between the sealing post 22 and the first hole 11 and between the boss 31 and the second hole 21 , the friction coefficient of the contact surface between the sealing post 22 and the first hole 11 is set to be greater than that between the boss 31 and the second hole 11 . The friction coefficient of the contact surfaces of the two holes 21 is that when the external force applied to the cover body 3 can make the cover body 3 rotate relative to the sealing member 2, due to the different friction coefficients, the force generated on the sealing member 2 when the cover body 3 rotates is not enough to make the cover body 3 rotate relative to the sealing member 2. The sealing member 2 rotates relative to the end cover 1, so the relative fixation of the sealing member 2 and the end cover 1 can be ensured, and the wear between the sealing member 2 and the end cover 1 can be reduced.

In other embodiments, the sealing post 22 is in an interference fit with the first hole 11 , the boss 31 is in an interference fit with the second hole 21 , and the amount of interference between the sealing post 22 and the first hole 11 is larger than the boss 31 The amount of interference with the second hole 21 .

The larger interference between the sealing column 22 and the first hole 11 can make the frictional force between the sealing column 22 and the first hole 11 larger, so that the sealing member 2 and the end cover 1 need to be subjected to a higher pressure than the cover body 3 . The rotation can only occur when a larger external force occurs relative to the sealing member 2, so when the cover body 3 rotates relative to the sealing member 2, the sealing member 2 and the end cover 1 can be relatively fixed.

On the premise of ensuring that the frictional force between the sealing post 22 and the first hole 11 is greater than the frictional force between the boss 31 and the second hole 21 , the interference between the sealing post 22 and the first hole 11 is larger than that between the boss 31 and the second hole 21 . In some embodiments of the interference between the platform 31 and the second hole 21 , the friction coefficient of the contact surface of the sealing post 22 and the first hole 11 may be equal to or greater than the friction coefficient of the contact surface of the boss 31 and the second hole 21 .

On the premise of ensuring that the frictional force between the sealing post 22 and the first hole 11 is greater than the frictional force between the boss 31 and the second hole 21 , the friction coefficient of the contact surface between the sealing post 22 and the first hole 11 is greater than that of the boss In some embodiments of the friction coefficient between the contact surface of 31 and the second hole 21 , the interference between the sealing post 22 and the first hole 11 may be equal to or greater than the interference between the boss 31 and the second hole 21 .

In still other embodiments, the sealing post 22 is in interference fit with the first hole 11 , the boss 31 is in interference fit with the second hole 21 , and the friction coefficient of the contact surface between the sealing post 22 and the first hole 11 is greater than that between the boss 31 and the second hole 11 . The friction coefficient between the contact surfaces of the two holes 21 , and the interference between the sealing post 22 and the first hole 11 is greater than the interference between the boss 31 and the second hole 21 . This structure can more effectively keep the sealing member 2 and the end cover 1 relatively fixed during the rotation of the cover body 3 relative to the sealing member 2.

In some embodiments, the sealing member 2 further includes a thrust table 23 connected to the sealing column 22 , the thrust table 23 is located between the cover body 3 and the end cover 1 , and the thrust table 23 is matched with the end surface of the first hole 11 .

The thrust table 23 has a predetermined thickness and can be sealed on the outer end surface of the first hole 11 . In the direction perpendicular to the axis of the first hole 11 , the cross-sectional area of the thrust table 23 is greater than or equal to the cross-sectional area of the first hole 11 . By providing the thrust table 23, the outer end of the first hole 11 can be effectively sealed, the electrolyte can be prevented from flowing out through the gap between the sealing column 22 and the first hole 11, and impurities can also be prevented from passing through the sealing column 22 and the first hole 11. The gaps between the holes 11 enter into the interior of the battery cells 600 .

In some embodiments, the mating surface between the thrust table 23 and the end surface of the first hole 11 is a plane. This structure is beneficial to make the thrust table 23 form close contact with the end face of the first hole 11 , achieve effective sealing between the thrust table 23 and the end face of the first hole 11 , and prevent electrolyte leakage or impurities from entering.

The following describes the matching structure of the cover body 3 and the end cover 1 in this application.

As shown in FIG. 4 , in some embodiments, the end cover 1 is provided with a second accommodating portion 12 arranged along the circumference of the first hole 11 , and the second accommodating portion 12 is used to accommodate at least part of the cover body 3 to realize the cover pairing. To limit the position of the body 3 , the second accommodating portion 12 is located on the side of the end cap 1 away from the interior of the battery cell 600 .

The second accommodating portion 12 can accommodate a part of the cover body 3 to limit the cover body 3, limit the degree of freedom of the cover body 3 in its height direction, prevent the cover body 3 from separating from the end cover 1, and realize the connection between the cover body 3 and the end cover 1. Relative fixation between covers 1. At the same time, the cover body 3 can also cover the sealing member 2 at least partially. Therefore, after the cover body 3 is restricted by the end cap 1 in its degree of freedom in the height direction, the sealing member 2 is also pressed under the cover body 3, which also realizes The fixing of the seal 2 is completed.

The second accommodating portion 12 is located on the side of the end cap 1 away from the housing 40 and is disposed along the circumference of the first hole 11 . The second accommodating portion 12 may be a cavity extending along a part of the circumference of the first hole 11 . There is a preset distance between the second accommodating portion 12 and the surface of the end cover 1 close to the inside of the housing 40 , and the size of the preset distance is not limited. or the lower region, so that at least part of the end cap 1 is located between the second accommodating portion 12 and the electrode assembly 30 , rather than opening the second accommodating portion 12 directly on the bottom surface of the end cap 1 .

As shown in FIGS. 4 to 18 , in some embodiments, the cover body 3 is rotatable relative to the end cap 1 and includes a limiting portion 33 . When the cover body 3 is rotated to the first position, the limiting portion 33 is located in the second accommodating portion 12 to limit the separation of the cover body 3 and the end cover 1; when the cover body 3 rotates to the second position, the limiting portion 33 and the second accommodating portion 12 are displaced along the circumferential direction of the first hole 11, so that the cover body 3 can be separated from the end cap 1. Separation of end cap 1.

The detachable connection between the end cover 1 and the cover body 3 can be achieved by providing the limiting portion 33 to cooperate with the second accommodating portion 12 . The cover body 3 includes a cover body main body portion 32 for covering at least part of the sealing member 2 . For example, the cover body main body portion 32 may be in a disc-shaped or annular structure or the like. The limiting portion 33 is disposed on the circumferential side surface of the cover main body portion 32 and extends radially outward. The number of the limiting parts 33 matches the number of the second accommodating parts 12 . In the embodiment shown in FIGS. 4 to 18 , the side surface of the main body portion 32 of the cover is provided with two spaced limiting portions 33 , and the end cover 1 is provided with two second accommodating portions 12 . The two limiting portions 33 is provided in a one-to-one correspondence with the two second accommodating portions 12 . In other embodiments, the number of the second accommodating portion 12 and the limiting portion 33 may also be more than two, such as three or four.

By arranging multiple limiting portions 33 , the cover body 3 has multiple limiting supports in the first position, which can be stably engaged by the second accommodating portion 12 and reduce the engaging force on the limiting portions 33 to ensure the limited strength of the bit portion 33. For example, the plurality of limiting portions 33 can be evenly distributed along the circumferential direction of the main body portion 32 of the cover body, which can make the force distribution of the cover body 3 along the entire circumferential direction more balanced, prevent the cover body 3 from tilting, and facilitate the smoothness of the secondary injection. Rotating the cover body 3 from the first position to the second position can also prevent the limiting portion 33 from scratching the sealing member 2 when the cover body 3 presses the sealing member 2 .

An engaging structure is formed between the limiting portion 33 and the second accommodating portion 12 , wherein when the cover body 3 rotates to the first position, the limiting portion 33 is partially or entirely located in the second accommodating portion 12 to limit the cover body 3 and the second accommodating portion 12 . The end cover 1 is separated to close the first hole 11 ; when the cover body 3 rotates to the second position in the clockwise or counterclockwise direction, the limiting portion 33 and the second accommodating portion 12 are displaced along the circumferential direction of the first hole 11 . , and the limiting part 33 is completely separated from the second accommodating part 12 to realize the separation of the cover body 3 and the end cover 1 , and the electrolyte can be injected in this state.

The cover body 3 is limited or separated from the second accommodating portion 12 by rotation. During the rotation, friction may occur between the limiting portion 33 and the inner wall of the second accommodating portion 12 , resulting in metal particles. Since the second accommodating portion 12 is located on the side of the end cap 1 away from the casing 40 in the present application, the metal particles generated during the rotation will not directly fall into the casing 40, resulting in a short circuit of the battery cells 600, which further improves the battery cell performance. body 600 security.

The extension length of the limiting portion 33 along the circumferential direction of the first hole 11 and the extension width along the radial direction of the first hole 11 ensure the strength of the engaging structure, and can also prevent damage to the engaging structure in the case of a large number of disassembly and assembly times . In addition, when the battery cell 600 is applied to the vehicle 100, since the vehicle 100 will vibrate during operation, the present application can prevent the limiting portion 33 from interacting with the second accommodating portion 12 by increasing the strength of the engagement between the limiting portion 33 and the second accommodating portion 12. The second accommodating portion 12 is damaged by vibration for a long time, so as to ensure the reliability and service life of the battery cell 600 in operation.

In the present application, the coupling or disengagement of the limiting portion 33 and the second accommodating portion 12 is realized by the rotation of the cover body 3 , the structure is simple, the requirement for the matching accuracy is low, and it can be used repeatedly; in terms of processing, the limiting portion is provided on the cover body 3 33. The second accommodating portion 12 provided on the end cover 1 is easy to process and suitable for lithium-ion batteries with a small overall size; in terms of assembly and maintenance, the disassembly and assembly of the cover body 3 is easy, and the assembly efficiency of the battery can be improved during production. , the maintenance time can be shortened during the second injection.

In some embodiments, the boss 31 and the second hole 21 are configured to be relatively rotatable at least during the process of rotating the cover body 3 from the first position to the second position.

The boss 31 and the second hole 21 may be configured to be partially rotatable relative to each other in the circumferential direction of rotation. For example, a limiting boss may be provided in the second hole 21 to limit the circumferential rotation of the boss 31; the boss 31 And the second hole 21 may also be provided so as to be relatively rotatable over the entire circumference in the circumferential direction of rotation. Setting the boss 31 and the second hole 21 to be partially rotatable relative to each other in the circumferential direction can effectively limit the rotation range, and the boss 31 and the second hole 21 can be rotated within a preset rotation range, which is beneficial to Control the limit position of rotation. However, if the boss 31 and the second hole 21 are set to be relatively rotatable over the entire circumference, the flexibility of rotation can be improved, and the operation is more convenient.

In some embodiments, the end cap 1 further includes a guide portion 13 that communicates with the second accommodating portion 12 , and the limiting portion 33 is used to enter the second accommodating portion 12 through the guide portion 13 , or communicate with the end cap 1 through the guide portion 13 . separation. By providing the guide portion, the limiting portion 33 can enter the second accommodating portion 12 or be separated from the end cover 1 more smoothly, thereby improving the convenience of operation and further improving the operation efficiency.

The guide portion 13 forms a channel through which the second accommodating portion 12 communicates with the outside of the end cap 1 . For example, a plurality of second accommodating portions 12 are provided along the circumferential direction, and the guiding portion 13 is an opening area formed between adjacent second accommodating portions 12. When the cover body 3 is in the second position, the limiting portion 33 and the second accommodating portion 12 is circumferentially offset and is located in the guide 13. Alternatively, only one second accommodating portion 12 is provided in the circumferential direction, and the guide portion 13 is an opening area other than the second accommodating portion 12 in the circumferential direction.

The circumferential length of the guide portion 13 can be greater than the circumferential length of the limiting portion 33, and not exceeding the circumferential length of the second accommodating portion 12, so as to increase the engagement length between the limiting portion 33 and the second accommodating portion 12 as much as possible, and increase the limit. Position stability, and the circumferential length of the guide portion 13 should enable the limiting portion 33 to smoothly enter the guide portion 13 .

In some embodiments, the end cap 1 is provided with a first groove 14 , the first groove 14 communicates with the first hole 11 , the opening area of the first groove 14 is larger than the opening area of the first hole 11 , and the first groove 14 is in communication with the first hole 11 . The groove 14 is used to accommodate the cover body 3, and the first groove 14 communicates with the guide portion 13. Placing the cover body 3 in the first groove 14 and rotating the cover body 3 can make the cover body 3 enter the second container through the guide portion 13. Section 12.

In some embodiments, the end cap 1 includes an end cap body 1A and an installation part 4 , the installation part 4 is disposed on the surface of the end cap body 1A and is disposed around the first hole 11 , and the second accommodating part 12 is disposed on the installation part 4 or The second accommodating portion 12 is formed by enclosing the mounting member 4 and the end cap body 1A. The mounting member 4 is mounted in the first groove 14 .

Since the thin plate-like structure of the end cap 1 is not easy to process complicated structures, it is easy to form the second accommodating portion 12 by arranging the mounting member 4 , which can reduce the processing difficulty of the end cap 1 .

The specific structure of the mounting member 4 in the present application will be introduced below with reference to FIGS. 20A to 21B .

As shown in FIG. 20A , it is a schematic diagram of the front structure of the installation component 4 in some embodiments; as shown in FIG. 20B , it is a schematic diagram of the rear structure of the installation component 4 in some embodiments; as shown in FIG. 21A , in some implementations The top view of the mounting member 4 in the example, as shown in FIG. 21B , is the AA cross-sectional view of the mounting member 4 in some embodiments.

The second accommodating portion 12 is provided on the mounting member 4 . The mounting part 4 includes a mounting ring 41 and a limit stand 43. The limit stand 43 is connected to the inner wall of the mounting ring 41 and extends radially inward. The mounting ring 41 is fixed on the end cover body 1A. A second accommodating portion 12 is formed between the cover bodies 1A. The mounting ring 41 can be an annular structure, and the first groove 14 is disposed in the center of the mounting ring 41 .

The second accommodating portion 12 includes a limiting wall 123 and a side wall 124 connected with the limiting wall 123 , and the bottom surface of the limiting platform 43 serves as the limiting wall 123 . When the cover body 3 rotates to the first position, the limiting wall 123 abuts against the limiting portion 33 , and the limiting wall 123 is a top wall, which can limit the freedom of the cover body 3 to move upward in the height direction, so as to limit the distance between the cover body 3 and the limiting portion 33 . End cap 1 is separated.

The limiting wall 123 is provided with an inclined surface 122 , and the inclined surface 122 is configured to gradually decrease in distance from the cover body 3 along the rotation direction of the cover body 3 from the second position to the first position. The inclined surface 122 may be disposed on one or both ends of the second accommodating portion 12 along the circumferential direction, so that the limiting portion 33 can smoothly enter the second accommodating portion 12 . For example, the inclined surface 122 may be a flat surface or a curved surface, or the like.

By arranging the inclined surface 122, the limiting portion 33 can smoothly enter the second accommodating portion 12, without the need for alignment adjustment, the assembly efficiency can be improved, and the collision between the limiting portion 33 and the entrance of the second accommodating portion 12 can be prevented. Thereby, the service life of the liquid injection components is improved, and the generation of metal chips is reduced.

The second accommodating portion 12 is provided with a stopper portion 125 configured to limit the maximum rotational stroke of the stopper portion 33 . A stopper portion 125 may be provided on each of the second accommodating portions 12 . The blocking portion 125 can block the rotation of the limiting portion 33 to prevent the limiting portion 33 from being directly rotated out of the second accommodating portion 12 .

When the maximum rotational stroke is reached, the side surface of the stopper portion 33 in the circumferential direction is in complete contact with the stopper portion 125 . For example, the main body portion 32 of the cover body is evenly provided with two limiting portions 33 along the circumferential direction, and the two side surfaces of the limiting portion 33 along the circumferential direction are both parallel to the central plane of the cover body 3 . Correspondingly, the two second accommodating portions 12 The stop portion 125 of the second hole 21 is centrally symmetric with respect to the center plane of the second hole 21 , and the two stop portions 125 are parallel to each other. Optionally, the side surface of the limiting portion 33 along the circumferential direction may also partially abut against the stop portion 125 .

In order to prevent the circumferential rotation of the mounting member 4 relative to the first groove 14 during installation, as shown in FIGS. 20A to 21B , the bottom of the mounting member 4 may be provided with a second groove 42 , for example, the second groove 42 may be provided in the mounting position Bottom of ring 41. Correspondingly, as shown in FIG. 22 , the position where the bottom wall and the side wall of the first groove 14 are connected is provided with a catch portion 141 , and the catch portion 141 cooperates with the second groove 42 to restrict the mounting member 4 relative to the first groove 42 . A groove 14 rotates circumferentially.

In some embodiments, the sealing member 2 can be deformed, and a highly elastic material resistant to electrolyte solution, such as rubber or other elastic plastics, is selected.

When the cover body 3 needs to be installed, a downward force is applied to the cover body 3, and a gap is generated between the limiting portion 33 and the limiting wall 123 through the deformation of the sealing member 2. At this time, the cover body 3 is rotated to make the limiting portion 33 smoothly enters the second accommodating portion 12, and after reaching the first position, release the cover 3, and the cover 3 moves upward under the elastic action of the seal 2 until the top surface of the limiting portion 33 abuts against the limiting wall 123 .

When the cover body 3 needs to be disassembled, a downward force is applied to the cover body 3, and a gap is generated between the limiting portion 33 and the limiting wall 123 through the deformation of the sealing member 2. At this time, the cover body 3 is rotated to make the limiting portion 33 is smoothly displaced from the second accommodating portion 12 in the circumferential direction and is integrally located in the guiding portion 13. At this time, when the second position is reached, the cover body 3 can be disassembled.

In some embodiments, a limiting structure is provided between the limiting portion 33 and the second accommodating portion 12 , and is configured to limit the dislocation and separation of the cover 3 from the second accommodating portion 12 when the cover body 3 is in the first position. If the device using the battery cell 600 generates a large vibration or impact during operation, the limiting structure can reliably engage the limiting portion 33 with the second accommodating portion 12 in the first position to prevent the limiting portion 33 from occurring. Circumferentially rotates away from the second accommodating portion 12 , which makes the connection between the cover body 3 and the end cover 1 more reliable, improves the sealing performance to the electrolyte, and thus ensures the reliability of the battery operation.

As shown in FIGS. 20A and 21A , the limiting structure includes: a third accommodating portion 332 and a limiting protruding portion 121 . The third accommodating portion 332 is provided on one of the limiting portion 33 and the second accommodating portion 12 , and the third accommodating portion 332 may be a hole or a groove; the limiting protrusion 121 is engaged with the third accommodating portion 332 , and is arranged on the other of the limiting portion 33 and the second accommodating portion 12 . When the cover body 3 is in the first position, under the elastic action of the sealing member 2, the third accommodating portion 332 and the limiting protrusion 121 are clamped tightly, so that the space between the limiting portion 33 and the second accommodating portion 12 will not be affected by Vibration, impact and other external forces are rotated and loosened; alternatively, the cover body 3 is clamped through the interference fit between the third accommodating portion 332 and the limiting protrusion portion 121 .

As shown in FIG. 20A, the limiting protrusion 121 is provided on the limiting wall 123 of the second accommodating portion 12; as shown in FIG. When the body 3 is in the first position, the limiting protrusion 121 is embedded in the third accommodating portion 332 to limit the rotation of the cover 3 .

In some embodiments, the sealing member 2 includes a sealing post 22 inserted into the first hole 11 , an end of the sealing post 22 close to the interior of the battery cell 600 is provided with a guiding inclined surface, the length of the guiding inclined surface along the axis direction of the first hole 11 It is longer than the length of the mounting member 4 in the axial direction of the first hole 11 . After this arrangement, before the sealing column 22 is inserted into the first hole 11, the contact between the sealing column 22 and the hole wall of the first hole 11 can be made prior to the contact between the sealing member 2 and the outer surface of the end cap 1, Thus, the wear between the sealing element 2 and the end cover 1 is reduced, and the sealing effect of the sealing element 2 is ensured. At the same time, the guiding slope has a guiding effect on the operation of inserting the sealing column 22 into the first hole 11 , which can improve the convenience of operation, thereby improving the accuracy and efficiency of operation.

Hereinafter, another matching structure of the cover body 3 and the end cover 1 in the present application will be introduced with reference to FIG. 23 .

As shown in FIG. 23, the end cap 1 includes an end cap body 1A and a liquid injection base 15. The end cap body 1A is provided with a first hole 11 and a first groove 14, and the bottom of the first groove 14 is provided with a first hole 11 and a first groove 14. A hole 11 communicates with the hole.

The liquid injection base 15 includes a bottom support plate 151 and a liquid injection part 152 mounted on the bottom support plate 151 . The bottom support plate 151 is disposed in the first groove 14 , and the bottom surface of the bottom support plate 151 is in contact with the bottom surface of the first groove 14 . At least part of the liquid injection part 152 is higher than the outer surface of the side of the end cap 1 away from the interior of the battery cell 600 .

The first hole 11 includes a first hole segment 11A provided on the liquid injection base 15 and a second hole segment 11B provided on the end cap body 1A. The first hole segment 11A and the second hole segment 11B communicate with each other. The second accommodating portion 12 is disposed on the outer side surface of the liquid injection portion 152 , the inner side of the cover body 3 is provided with an engaging portion, and the cover body 3 is in the shape of a circular cap.

The sealing column 22 is inserted into the first hole section 11A and the second hole section 11B, the bottom surface of the thrust table 23 abuts on the top surface of the liquid injection part 152, the cover body 3 covers the upper part of the sealing member 2, and the cover body 3 is rotated by rotating the cover body 3. , the engaging part enters into the second accommodating part 12 , the connection between the cover body 3 and the end cover 1 is realized through the cooperation between the engaging part and the second accommodating part 12 , and the sealing member 2 is pressed against the cover body 3 and the end cover 1 at the same time. In between, the fixing of the sealing member 2 is realized.

Wherein, the number of the engaging portion and the second accommodating portion 12 is equal, for example, one, two, or three.

Different embodiments of the matching structure of the sealing member 2 and the cover body 3 in the present application will be described in detail below with reference to FIGS. 4 to 19B .

As shown in FIGS. 4 to 9 , they are schematic structural diagrams of the first embodiment.

In the first embodiment, as shown in FIGS. 5 and 6 , the sealing member 2 is provided with a second hole 21 , and the sealing member 2 includes a sealing column 22 and a thrust table 23 connected with the sealing column 22 . The sealing column 22 and the thrust table 23 may be two independent parts and connected to each other; the sealing column 22 and the thrust table 23 may also be an integral structure formed in one piece.

The second hole 21 extends from the end of the thrust table 23 away from the sealing column 22 toward the direction close to the sealing column 22 . The second hole 21 penetrates the thrust table 23 and extends to the sealing column 22 . The second hole 21 is a blind hole.

The wall of the second hole 21 is located at the end of the thrust table 23 away from the sealing column 22 with a chamfer 211 . By setting the chamfer 211 , the boss 31 inserted into the second hole 21 can be guided to improve assembly efficiency. The chamfer 211 has an arc shape, and the opening area of the chamfer 211 gradually increases along the direction away from the sealing column 22 , so that the boss 31 can be inserted smoothly. In addition to the chamfer 211 , the second hole 21 includes a cylindrical hole section of equal diameter and a reduced-diameter hole section, and the reduced-diameter hole section is disposed at one end of the cylindrical hole section away from the chamfer 211 .

In the first embodiment, the ratio of the length of the second hole 21 to the entire length of the sealing member 2 is less than 50%. The length of the second hole 21 is slightly larger than the length of the boss 31 .

The sealing column 22 includes a sealing body part 221 and a cone part 222 connected with the sealing body part 221 . The sealing body part 221 and the cone part 222 can be two relatively independent parts connected to each other, or can be integrally formed. The cross-sectional area of the tapered portion 222 gradually decreases in the direction away from the thrust table 23 . One end of the tapered portion 222 away from the thrust table 23 is flat.

By arranging the tapered portion 222, the sealing column 22 can be guided when the sealing column 22 is inserted into the first hole 11, which facilitates the insertion of the sealing column 22 and improves the assembly efficiency.

The sealing column 22 is further provided with a weight-reducing concave portion 223 , and the weight-reducing concave portion 223 may be disposed on the sealing body portion 221 . The weight-reducing concave portion 223 extends from the outer surface of the sealing body portion 221 in a direction close to the central axis of the sealing body portion 221 . A plurality of weight-reducing recesses 223 may be provided in the circumferential direction of the sealing column 22 to reduce the overall weight of the sealing member 2 .

The thrust table 23 is also in the shape of a cylinder, and the height of the thrust table 23 is smaller than the height of the sealing column 22 .

As shown in FIGS. 7 to 9 , the cover body 3 is provided with a boss 31 , and the cover body 3 includes a cover body main body portion 32 and a limiting portion 33 connected to the cover body main body portion 32 . The limiting portion 33 and the cover main body portion 32 may be two relatively independent parts connected to each other, or may be integrally formed. In the first embodiment, two limiting portions 33 are connected to the outer periphery of the main body portion 32 of the cover body.

The first end of the cover body portion 32 is provided with a third groove 321 extending from the end of the first end to the interior of the cover body portion 32. For example, the cross-sectional shape of the third groove 321 is hexagonal, which is convenient for using tools The lid body 3 is rotated. A side of the limiting portion 33 close to the first end of the main body portion 32 of the cover is provided with a third accommodating portion 332 extending from the side to the interior of the limiting portion 33 . For example, the cross-sectional shape of the third accommodating portion is Oval.

The boss 31 is provided at the second end of the cover body part 32 opposite to the first end, and the second end of the cover body body part 32 is provided with a fourth accommodating part extending from the second end to the interior of the cover body body part 32 331 , the boss 31 is disposed on the bottom wall of the fourth accommodating portion 331 . The boss 31 extends from the bottom wall of the fourth accommodating portion 331 in a direction away from the main body portion 32 of the cover.

The opening area of the fourth receiving portion 331 is larger than the cross-sectional area of the boss 31 . The opening area of the fourth accommodating portion 331 is also larger than the cross-sectional area of the thrust table 23 of the sealing member 2 , so as to accommodate the thrust table 23 in the fourth accommodating portion 331 . By arranging the fourth accommodating portion 331 , space can be reserved for the thrust table 23 .

In the axial direction of the second hole 21 , the height of the fourth accommodating portion 331 is less than or equal to the height of the thrust table 23 , and this structure can press the thrust table 23 when the sealing member 2 and the cover body 3 are assembled. , improve the sealing effect.

In the first embodiment, the boss 31 is in the shape of a cylinder and is in the shape of an equal-diameter cylinder. The end of the boss 31 away from the main body portion 32 of the cover is provided with a circular arc chamfer to prevent the boss 31 from bumping into the second hole 21 and generating particles.

As shown in FIG. 4 , the sealing column 22 is inserted into the first hole 11 , the length of the sealing column 22 is greater than the length of the first hole 11 , and part of the sealing column 22 extends into the side of the end cap 1 close to the interior of the battery cell 600 . The end surface of the thrust table 23 close to the sealing column 22 is in contact with the end surface of the end cap 1 away from the interior of the battery cell 600 . The boss 31 is inserted into the second hole 21 , and the thrust plate 23 is accommodated in the fourth accommodating portion 331 .

As shown in FIGS. 10-11 , it is a schematic structural diagram of the second embodiment.

In the second embodiment, as shown in FIG. 11 , the sealing member 2 is provided with a second hole 21 , and the sealing member 2 includes a sealing column 22 and a thrust table 23 connected with the sealing column 22 . The sealing column 22 and the thrust table 23 may be two independent parts and connected to each other; the sealing column 22 and the thrust table 23 may also be an integral structure formed in one piece.

The end of the second hole 21 located at the thrust table 23 away from the sealing column 22 is provided with a chamfer 211 . By setting the chamfer 211 , the boss 31 inserted into the second hole 21 can be guided to improve assembly efficiency. The chamfer 211 has an arc shape, and the opening area of the chamfer 211 gradually increases along the direction away from the sealing column 22 , so that the boss 31 can be inserted smoothly. In addition to the chamfer 211 , the second hole 21 includes a cylindrical hole section of equal diameter and a reduced-diameter hole section, and the reduced-diameter hole section is disposed at one end of the cylindrical hole section away from the chamfer 211 .

In the second embodiment, the length of the second hole 21 accounts for more than 90% of the entire length of the sealing member 2 . A thin wall 2221 is formed between the bottom wall of the second hole 21 and the bottom wall of the sealing column 22. This structure can make it easier for the operator to pierce the sealing member 2 through the needle-shaped member, so that before disassembling the sealing member 2, a thin wall 2221 is formed The small hole formed by piercing the thin wall 2221 releases the air pressure inside the battery cell 600 to prevent the operator from being impacted due to too high internal air pressure when the sealing member 2 is directly disassembled.

As shown in FIG. 10 , the structure of the cover body 3 and the matching manner of the cover body 3 and the sealing member 2 are the same as the structure of the cover body 3 in the first embodiment, and will not be repeated.

As shown in Figures 12-14, it is a schematic structural diagram of the third embodiment.

As shown in FIG. 13 , the sealing member 2 is provided with a second hole 21 , and the sealing member 2 includes a sealing column 22 and a thrust table 23 connected with the sealing column 22 . The sealing column 22 and the thrust table 23 may be two independent parts and connected to each other; the sealing column 22 and the thrust table 23 may also be an integral structure formed in one piece.

The end of the second hole 21 located at the thrust table 23 away from the sealing column 22 is provided with a chamfer 211 . By setting the chamfer 211 , the boss 31 inserted into the second hole 21 can be guided to improve assembly efficiency. The chamfer 211 has an arc shape, and the opening area of the chamfer 211 gradually increases along the direction away from the sealing column 22 , so that the boss 31 can be inserted smoothly.

The second hole 21 includes a first accommodating portion 212 , a second accommodating portion 213 , a first extending portion 214 and a second extending portion 215 connected in sequence from the chamfer 211 . The cross-sectional area of the first accommodating portion 212 gradually increases along the direction away from the chamfer 211 , the cross-sectional area of the second accommodating portion 213 first increases and then decreases along the direction away from the chamfer 211 , and the first extension portion 214 is of equal diameter , the cross-sectional area of the second extension portion 215 gradually decreases along the direction away from the chamfer 211 .

By arranging the first extension portion 214 and the second extension portion 215 , the length of the second hole 21 accounts for more than 90% of the overall length of the sealing member 2 . A thin wall 2221 is formed between the bottom wall of the second hole 21 and the bottom wall of the sealing column 22. This structure can make it easier for the operator to pierce the sealing member 2 through the needle-shaped member, so that before disassembling the sealing member 2, the The small hole formed by piercing the thin wall 2221 releases the air pressure inside the battery cell 600 to prevent the internal air pressure from being too high and causing an impact to the operator.

In the third embodiment, the ratio of the length of the second hole 21 to the entire length of the sealing member 2 is greater than 90%. A thin wall 2221 is formed between the bottom wall of the second hole 21 and the bottom wall of the sealing column 22. This structure can make it easier for the operator to pierce the sealing member 2 through the needle-shaped member, so that before disassembling the sealing member 2, the The small hole formed by piercing the thin wall 2221 releases the air pressure inside the battery cell 600 to prevent the internal air pressure from being too high and causing an impact to the operator.

The sealing column 22 includes a sealing body part 221 and a cone part 222 connected with the sealing body part 221 . The sealing body part 221 and the cone part 222 can be relatively independent parts and connected to each other, or can be integrally formed. The cross-sectional area of the tapered portion 222 gradually decreases in the direction away from the thrust table 23 . One end of the tapered portion 222 away from the thrust table 23 is flat.

As shown in FIG. 14 , the cover body 3 is provided with a boss 31 , and the cover body 3 includes a cover body main body portion 32 and a limiting portion 33 connected to the cover body main body portion 32 . The limiting portion 33 and the cover main body portion 32 may be two relatively independent parts connected to each other, or may be integrally formed. In the third embodiment, two limiting portions 33 are connected to the outer periphery of the main body portion 32 of the cover.

The first end of the cover body part 32 is provided with a third groove 321 extending from the end of the first end to the interior of the cover body body part 32. For example, the cross-sectional shape of the third groove 321 is hexagonal, which is convenient for using tools The lid body 3 is rotated. A side of the limiting portion 33 close to the first end of the main body portion 32 of the cover is provided with a third accommodating portion 332 extending from the side to the interior of the limiting portion 33 . For example, the cross-sectional shape of the third accommodating portion is Oval.

In the third embodiment, the boss 31 includes a first insertion portion 311 , and in a direction perpendicular to the axis of the second hole 21 , the cross-sectional area of the first insertion portion 311 gradually increases in a direction away from the cover main body portion 32 , the cross-sectional shape of the first insertion portion 311 along the axis direction of the second hole 21 is a trapezoid.

The end of the first insertion portion 311 away from the main body portion 32 of the cover body is provided with a circular arc chamfering, so as to avoid the bumping of the boss 31 into the second hole 21 and the generation of particulate matter.

As shown in FIG. 12 , the first insertion portion 311 is inserted into the first accommodating portion 212 of the second hole 21 , the first extension portion 214 and the second extension portion 215 are not inserted into solid structures, and the thrust table 23 is accommodated in the fourth accommodating portion 215 . Section 331. Such a structure can effectively restrict the separation of the sealing member 2 and the cover body 3 from each other through the cooperation of the first insertion portion 311 and the first accommodating portion 212 .

As shown in FIGS. 15-18 , they are schematic structural diagrams of the fourth embodiment.

As shown in FIG. 16 , the sealing member 2 is provided with a second hole 21 , and the sealing member 2 includes a sealing column 22 and a thrust table 23 connected with the sealing column 22 . The sealing column 22 and the thrust table 23 may be two independent parts and connected to each other; the sealing column 22 and the thrust table 23 may also be an integral structure formed in one piece.

The second hole 21 includes a third extension part 216 , a first accommodating part 212 , a first extension part 214 and a second extension part 215 connected in sequence from the chamfer 211 . The three extending parts 216 are cylindrical hole segments of equal diameter, and the first receiving part 212 is also a cylindrical hole segment of equal diameter. The diameters of the first extension portion 214 and the third extension portion 216 are equal, and the cross-sectional area of the second extension portion 215 gradually decreases along the direction away from the chamfer 211 .

In the fourth embodiment, the length of the second hole 21 accounts for more than 90% of the entire length of the sealing member 2 . A thin wall 2221 is formed between the bottom wall of the second hole 21 and the bottom wall of the sealing column 22. This structure can make it easier for the operator to pierce the sealing member 2 through the needle-shaped member, so that before disassembling the sealing member 2, the The small hole formed by piercing the thin wall 2221 releases the air pressure inside the battery cell 600 to prevent the internal air pressure from being too high and causing an impact to the operator.

As shown in FIGS. 17 and 18 , the cover body 3 is provided with a boss 31 , and the cover body 3 includes a cover body main body portion 32 and a limiting portion 33 connected with the cover body main body portion 32 . The limiting portion 33 and the cover main body portion 32 may be two relatively independent parts connected to each other, or may be integrally formed. In the fourth embodiment, two limiting portions 33 are connected to the outer periphery of the main body portion 32 of the cover body.

In the fourth embodiment, the boss 31 includes a second insertion portion 312 connected to the cover main body portion 32 and a first insertion portion 311 connected to the second insertion portion 312, and the second insertion portion 312 is connected to the first insertion portion One end of 311 away from the main body portion 32 of the cover. The first insertion portion 311 and the second insertion portion 312 are both cylindrical shapes with equal diameters, and the diameter of the first insertion portion 311 is larger than the diameter of the second insertion portion 312 . The length of the first insertion portion 311 is smaller than the length of the second insertion portion 312 .

As shown in FIG. 15 , the second insertion portion 312 is inserted into the third extension portion 216 , the first insertion portion 311 is inserted into the first accommodating portion 212 of the second hole 21 , and the first extension portion 214 and the second extension portion 215 are not inserted. Inserted into the solid structure, the thrust table 23 is accommodated in the fourth accommodating portion 331 . Such a structure can effectively restrict the separation of the sealing member 2 and the cover body 3 from each other through the cooperation of the first insertion portion 311 and the first accommodating portion 212 .

19A and 19B are schematic structural diagrams of the fifth embodiment.

In the fifth embodiment, the sealing member 2 is provided with a second hole 21 , and the sealing member 2 includes a sealing column 22 and a thrust table 23 connected with the sealing column 22 . In the direction perpendicular to the axis of the second hole 21, the cross section of the sealing column 22 is elliptical, that is, the sealing column 22 is a non-rotating body. This structure can effectively prevent the sealing column 22 from rotating relative to the end cover 1 and reduce the sealing effect. Wear of piece 2.

For other structures on the sealing member 2 and the structure of the cover body 3, reference may be made to the above-mentioned first to fourth embodiments, which will not be repeated.

Based on the improvements to the end cap assembly 10 in the above embodiments, the present application further provides a case assembly for a battery cell 600, as shown in FIG. 24, the case assembly includes a case 40, a seal 2 and The cover body 3, the casing 40 are used for connecting with the end cover 1 to form the outer casing 50 of the battery cell 600, the casing 40 is provided with a first hole 11 for injecting electrolyte, the sealing member 2 is used for sealing the first hole 11, the cover The body 3 is used to cover at least part of the sealing member 2 , and the cover body 3 is rotatable relative to the end cap 1 to realize the detachable connection between the cover body 3 and the end cap 1 .

Wherein, one of the sealing member 2 and the cover body 3 is provided with a second hole 21, and the other of the sealing member 2 and the cover body 3 is provided with a boss 31, and the boss 31 is used for inserting into the second hole 21 and the boss 31 and the second hole 21 can rotate relative to each other, so as to realize the rotatable connection between the sealing member 2 and the cover body 3 .

In some embodiments, the first hole 11 is provided on the side of the housing 40 , and the sealing member 2 and the cover 3 are correspondingly provided on the side of the housing 40 . This structure can facilitate the injection of the electrolyte, and at the same time, it can provide a larger space for the arrangement of the electrode terminals 5 and the explosion-proof member 6 on the end cap 1 .

One difference between the housing assembly and the end cap assembly 10 is that in the housing assembly, the first hole 11 is provided on the housing 40 ; while in the end cap assembly 10 , the first hole 11 is provided on the end cap 1 . In the housing assembly, the structures of the sealing member 2 and the cover body 3 may refer to the structures of the sealing member 2 and the cover body 3 in the end cap assembly 10, which will not be repeated here.

Based on the above-mentioned end cap assembly 10 or housing assembly, the present application also provides a battery cell 600 .

In some embodiments, the battery cell 600 provided by the present application includes an electrode assembly 30 and a casing 50 for accommodating the electrode assembly 30 , the casing 50 includes a casing 40 and an end cap assembly 10 , and the end of the casing 40 has an opening 41 , the end cap assembly 10 covers the opening 41 at the end of the housing 40 .

In other embodiments, the battery cell 600 provided by the present application includes an electrode assembly 30 and a casing 50 for accommodating the electrode assembly 30 , the casing 50 includes an end cap 1 and a casing assembly, and the end of the casing 40 has an opening 41 , the end cover 1 covers the opening 41 at the end of the casing 40 .

In the battery cell 600 provided by the present application, the sealing member 2 and the cover body 3 are rotatably connected, and the sealing member 2 and the cover body 3 can be assembled or disassembled as a whole, which greatly simplifies the operation steps, shortens the operation time, and improves the operation efficiency. .

As shown in FIG. 25 , the present application also provides a liquid injection method for a battery cell 600, including:

Step S101: injecting electrolyte through the first hole 11 on the casing 50 of the battery cell 600;

Step S102: Take the sealing member 2 and the cover body 3 in the connected state to the first hole 11, and seal the first hole 11 through the sealing member 2 while the sealing member 2 and the cover body 3 are kept connected, and pass the cover body. 3 covering at least part of the seal 2; and

Step S103 : Rotate the cover body 3 relative to the sealing member 2 to realize the relative fixation of the cover body 3 and the housing 50 .

When assembling the sealing element 2 and the cover body 3, the sealing element 2 and the cover body 3 in the connected state are taken together to the first hole 11. Compared with the operation steps of taking the sealing element 2 first and then the cover body 3, In other words, it can greatly save the taking time, and at the same time, the sealing element 2 and the cover body 3 can be pre-assembled together, and the time for assembling the sealing element 2 and the cover body 3 can be saved when sealing is performed after liquid injection, thereby Improve assembly efficiency.

In some embodiments, the liquid injection method further includes:

The cover body 3 and the sealing member 2 remaining in the connected state are removed from the housing 50 .

When the cover body 3 and the sealing member 2 are disassembled, they are also removed as a whole, which can significantly simplify the operation steps and improve the operation efficiency compared with the way of disassembling them individually.

In some embodiments, the sealing member 2 is provided with a second hole 21 , the cover body 3 is provided with a boss 31 , the boss 31 is inserted into the second hole 21 , and the second hole 21 is a blind hole. Before the electrolyte is injected into the first hole 11 on the casing 50, the injection method further includes:

Pierce the bottom wall of the second hole 21 so that the second hole 21 communicates the inside of the battery cell 600 with the external environment to release the pressure inside the battery cell 600; and

The cover 3 and seal 2 are removed from the housing 50 .

In this embodiment, by piercing the bottom wall of the second hole 21 , the battery cells can be released before the cover body 3 and the sealing member 2 are removed from the casing 50 to open the first hole 11 The air pressure inside the 600 can prevent the operator from being impacted or injured due to the high air pressure, and can also avoid the loss of the electrolyte caused by the electrolyte rushing out of the battery cell 600 under the air pressure.

In some embodiments, the liquid injection method further includes:

Rotate the cover body 3 from the first position to the second position, so that the limiting portion 33 of the cover body 3 and the second accommodating portion 12 on the side of the casing 50 away from the interior of the battery cell 600 are displaced along the circumferential direction of the first hole 11 ;and

When the cover body 3 is rotated from the second position to the first position, the limiting portion 33 enters the second accommodating portion 12 to limit the separation of the cover body 3 and the sealing member 2 from the housing 50 .

In this embodiment, the cover body 3 and the end cover 1 are detachably connected by means of rotation, which is convenient to operate. On the premise that the cover body 3 and the end cover 1 are connected or disassembled in a rotational manner, the cover body 3 and the sealing member 2 are rotatably connected, so that the cover body 3 can be rotated relative to the end cover 1 during the rotation process of the cover body. 3. Rotating relative to the sealing member 2 at the same time is conducive to maintaining the relative fixation of the sealing member 2 and the end cover 1, reducing the wear between the sealing member 2 and the end cover 1, and helping to ensure the sealing effect of the sealing member 2.

In some embodiments, the liquid injection method further includes:

Rotate the cover body 3 from the first position to the second position, so that the limiting portion and the second accommodating portion 12 are displaced along the circumferential direction of the first hole 11; and

As shown in FIG. 26, the present application also provides a liquid injection device 700 for the battery cell 600, including:

The liquid injection mechanism 701 is used for injecting the electrolyte into the casing 50 through the first hole 11 provided on the casing 50; and

The disassembly and assembly mechanism 702 is used to take the seal 2 and the cover 3 in the connected state to the first hole 11 before the first hole 11 is sealed by the seal 2, and the seal 2 and the cover 3 are kept connected. In the state, the first hole 11 is sealed by the sealing member 2, at least part of the sealing member 2 is covered by the cover body 3, and after the sealing member 2 and the first hole 11 are matched, the cover body 3 is driven to rotate relative to the sealing member 2, so as to realize the cover The relative fixation of the body 3 and the housing 50.

In this embodiment, the sealing member 2 and the cover body 3 are always kept connected, and the whole of the sealing member 2 and the cover body 3 can be quickly disassembled and installed through the disassembly and assembly mechanism 702, and the operation efficiency is high.

The above-mentioned protection themes and features of the embodiments of the present application can be used for reference from each other, and those skilled in the art can flexibly combine the technical features of different embodiments to form more embodiments if the structure allows .

The battery end cap assembly, the battery and the electrical device provided by the present application have been described in detail above. The principles and implementations of the present application are described herein by using specific embodiments, and the descriptions of the above embodiments are only used to help understand the methods and core ideas of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the principles of the present application, several improvements and modifications can also be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

An end cap assembly (10) for a battery cell (600), comprising:

an end cap (1), provided with a first hole (11) for injecting electrolyte;

a seal (2) for sealing the first hole (11); and

A cover body (3) for covering at least part of the sealing member (2), and the cover body (3) is rotatable relative to the end cover (1) to realize the connection between the cover body (3) and the Detachable connection of the end cap (1);

Wherein, one of the sealing member (2) and the cover body (3) is provided with a second hole (21), and the other of the sealing member (2) and the cover body (3) is provided with a second hole (21). A boss (31), the boss (31) is used to be inserted into the second hole (21) and the boss (31) and the second hole (21) are relatively rotatable, so as to realize the The sealing element (2) is rotatably connected with the cover body (3).
The end cap assembly (10) according to claim 1, wherein the boss (31) and the second hole (21) are in interference fit to realize the connection between the two.
The end cap assembly (10) according to claim 1 or 2, wherein the boss (31) comprises a first insertion portion (311), and a hole wall of the second hole (21) is provided with a first An accommodating part (212), the first inserting part (311) is accommodated in the first accommodating part (212), so as to limit the separation of the sealing member (2) and the cover body (3).
The end cap assembly (10) according to claim 3, wherein, in a direction perpendicular to the axis of the second hole (21), the cross-sectional area of the first receiving portion (212) extends away from the The direction of the inserted end of the second hole (21) gradually increases, and the first insertion part (311) cooperates with the first accommodating part (212) to restrict the sealing member (2) and the cover body (3) Break away.
The end cap assembly (10) according to any one of claims 2-4, wherein the second hole (21) is a blind hole.
The end cap assembly (10) according to any one of claims 1-5, wherein the seal (2) and the end cap (1) are in the circumferential direction of the first hole (11) relatively fixed.
The end cap assembly (10) according to any one of claims 1-6, wherein the axis of rotation of the cap body (3) relative to the sealing member (2) and the axis of the first hole (11) Axes are collinear.
The end cap assembly (10) according to any one of claims 1-7, wherein the sealing member (2) comprises a sealing post (22) inserted into the first hole (11).
The end cap assembly (10) according to claim 8, wherein the sealing column (22) is a non-rotating body, and the shape of the first hole (11) is matched with the sealing member (2).
The end cap assembly (10) according to claim 8 or 9, wherein the sealing post (22) is an interference fit with the first hole (11).
The end cap assembly (10) according to claim 10, wherein the boss (31) is in an interference fit with the second hole (21), and the sealing post (22) is in an interference fit with the first hole (11) The friction coefficient of the contact surface is greater than the friction coefficient of the contact surface of the boss (31) and the second hole (21).
The end cap assembly (10) according to claim 8, wherein the sealing member (2) further comprises a thrust platform (23) connected with the sealing column (22), the thrust platform (23) Located between the cover body (3) and the end cover (1), the thrust table (23) is matched with the end face of the first hole (11).
The end cap assembly (10) according to any one of claims 1-12, wherein the boss (31) is a rotary body.
The end cap assembly (10) according to any one of claims 1-13, wherein the end cap (1) is provided with a second receiving portion (12) arranged along the circumference of the first hole (11). ), the second accommodating part (12) is used for accommodating at least part of the cover body (3) to realize the position limit of the cover body (3), and the second accommodating part (12) is located at the end The side of the cover (1) remote from the interior of the battery cell (600).
The end cap assembly (10) according to claim 14, wherein the cap body (3) is rotatable relative to the end cap (1) and includes a limiting portion (33), and the cap body (3) When rotated to the first position, the limiting portion (33) is located in the second accommodating portion (12) to limit the separation of the cover (3) from the end cover (1); (3) When rotated to the second position, the limiting portion (33) and the second accommodating portion (12) are displaced along the circumferential direction of the first hole (11), so as to realize the cover body (3) ) from the end cap (1).
The end cap assembly (10) of claim 15, wherein the boss (31) and the second hole (21) are adapted to rotate at least when the cap (3) is rotated from the first position Relative rotation is possible during the process to the second position.
The end cap assembly (10) according to claim 15, wherein the end cap (1) further comprises a guide portion (13) that communicates with the second accommodating portion (12), and the limiting portion ( 33) For entering the second accommodating part (12) through the guiding part (13), or separating from the end cap (1) through the guiding part (13).
The end cap assembly (10) according to claim 15, wherein the end cap (1) comprises an end cap body (1A) and a mounting part (4), the mounting part (4) being provided on the end cap The surface of the main body (1A), and is arranged around the first hole (11), the second accommodating part (12) is arranged on the mounting part (4) or the second accommodating part (12) is formed by the The mounting part (4) is formed by enclosing the end cap body (1A).
The end cap assembly (10) according to claim 18, wherein the sealing member (2) comprises a sealing post (22) inserted into the first hole (11), the sealing post (22) being adjacent to the The inner end of the battery cell (600) is provided with a guide slope, and the length of the guide slope along the axis of the first hole (11) is greater than that of the mounting member (4) along the first hole (11). ) in the axial direction.
A housing assembly for a battery cell (600), comprising:

A casing (40) for connecting with the end cap (1) to form a casing (50) of the battery cell (600), the casing (40) is provided with a first hole (11) for injecting electrolyte ;

a seal (2) for sealing the first hole (11); and

A cover body (3) for covering at least part of the sealing member (2), and the cover body (3) is rotatable relative to the end cover (1) to realize the connection between the cover body (3) and the Detachable connection of the end cap (1);

Wherein, one of the sealing member (2) and the cover body (3) is provided with a second hole (21), and the other of the sealing member (2) and the cover body (3) is provided with a second hole (21). A boss (31), the boss (31) is used to be inserted into the second hole (21) and the boss (31) and the second hole (21) are relatively rotatable, so as to realize the The sealing element (2) is rotatably connected with the cover body (3).
A battery cell (600), comprising:

An electrode assembly (30) and a casing (50) for accommodating the electrode assembly (30), the casing (50) comprising a casing (40) and an end cap assembly (50) according to any one of claims 1-19 10), the end of the casing (40) has an opening (41), and the end cap assembly (10) covers the opening (41) at the end of the casing (40); or,

An electrode assembly (30) and a housing (50) for accommodating the electrode assembly (30), the housing (50) comprising an end cap (1) and a housing assembly according to claim 20, the housing The end of (40) has an opening (41), and the end cover (1) covers the opening (41) of the end of the housing (40).
A battery (400) comprising a plurality of battery cells (600) as claimed in claim 21.
An electrical device, comprising the battery cell (600) of claim 21, wherein the battery cell (600) is used to provide electrical energy.
A liquid injection method for a battery cell (600), comprising:

The electrolyte is injected through the first hole (11) on the casing (50) of the battery cell (600);

Take the seal (2) and the cover (3) in the connected state to the first hole (11), and keep the seal (2) and the cover (3) connected The first hole (11) is sealed by the seal (2), and at least part of the seal (2) is covered by the cover (3); and

The cover body (3) is rotated relative to the sealing member (2) to achieve the relative fixation of the cover body (3) and the casing (50).
The liquid injection method according to claim 24, further comprising:

The cover body (3) and the sealing member (2) in the connected state are removed from the housing (50).
The liquid injection method according to claim 24, wherein the sealing member (2) is provided with a second hole (21), the cover body (3) is provided with a boss (31), and the boss (31) is inserted into In the second hole (21), the second hole (21) is a blind hole, and before the electrolyte is injected through the first hole (11) on the casing (50) of the battery cell (600), the The injection method also includes:

Pierce the bottom wall of the second hole (21) so that the second hole (21) communicates the inside of the battery cell (600) with the external environment, so as to release the inside of the battery cell (600) pressure; and

The cover (3) and the seal (2) are removed from the housing (50).
The liquid injection method according to claim 24, further comprising:

Rotate the cover body (3) from the first position to the second position, so that the limiting part (33) of the cover body (3) and the casing (50) are away from the interior of the battery cell (600) The second accommodating portion (12) on one side of the first hole (11) is displaced along the circumferential direction of the first hole (11); and

Rotate the cover (3) from the second position to the first position, so that the limiting portion (33) enters the second accommodating portion (12), so as to limit the cover (3) and the The seal (2) is separated from the housing (50).
The liquid injection method according to claim 27, further comprising:

Rotate the cover body (3) from the first position to the second position, so that the limiting portion (33) and the second accommodating portion (12) are along the length of the first hole (11). circumferential misalignment; and

The cover body (3) and the sealing member (2) in the connected state are removed from the housing (50).
A liquid injection device (700) for a battery cell (600), comprising:

A liquid injection mechanism (701) for injecting electrolyte into the casing (50) through the first hole (11) provided on the casing (50); and

A disassembly and assembly mechanism (702) is used for taking the sealing member (2) and the cover body (3) in a connected state to the first hole (11) by the sealing member (2) before sealing the first hole (11). a hole (11), and the first hole (11) is sealed by the sealing member (2) under the condition that the sealing member (2) and the cover body (3) remain connected, and the first hole (11) is sealed through the cover The body (3) covers at least part of the sealing member (2), and after the sealing member (2) is engaged with the first hole (11), the cover body (3) is driven relative to the sealing member (2) Rotate to achieve the relative fixation of the cover body (3) and the housing (50).